The procedures for changing the existing borders of Soviet republics were stipulated in the constitutions of the USSR and in Constitutions of Soviet Republics. According to article 78 of the USSR Constitution of 1977, the territory of a Soviet Republic could not be altered without its consent. The borders between Union Republics could only be redrawn by mutual agreement of the republics concerned, subject to approval by the higher legislative bodies of the USSR. This provision was also stipulated in the Constitutions of the Azerbaijan SSR and Armenia SSR.
Accordingly, the 20 February 1988 appeal to cede the then Nagorno-Karabakh Autonomous Oblast (NKAO) from Azerbaijan SSR to Armenia SSR was rejected by both the Supreme Council of Azerbaijan SSR and the Supreme Council of the USSR in their respective decisions of 17 June and 18 July of 1988. In other words, it was confirmed that NKAO formed part of the Azerbaijan SSR.
Armenia SSR was adamant in its attempts to annex NKAO through other illegal means. Its highest legislative body adopted several decisions in direct violation of the USSR Constitution and other key normative legal acts. Among them was the decision on the unification of Armenia SSR and NKAO, adopted on 1 December 1989 by the Supreme Soviet of Armenia SSR. However, on 10 January 1990, the Presidium of the Supreme Soviet of the USSR adopted a resolution on the “Nonconformity with the USSR Constitution of the Acts on Nagorno-Karabakh on 1 December 1989 and 9 January 1990” declaring the illegality of the claimed unification of Armenia with NKAO without the consent of the Azerbaijan SSR.
Armenia’s reference to the Law of the USSR “On the Procedures for Resolving Questions Related to the Secession of Union Republics from the USSR” of 3 April 1990 also provides no support to its position. In fact, although the formal objective of the Law was to regulate mutual relations within the framework of the USSR by establishing specific guidelines to be followed by Union Republics in the event of their secession from the USSR, the true intention behind that Act, hastily adopted shortly before the Soviet Union ceased to exist, was to create serious barriers to the path of secession of Union Republics and thus prevent the dissolution of the USSR.
During the short period from the adoption of the Law until the formal dissolution of the USSR, none of the Union Republics resorted to the secession procedure stipulated in it. For these reasons, the Law of 3 April 1990 was never applied. Instead, it was rapidly superseded by the dramatic events in the USSR and lost any legal effect even before the Soviet Union had ceased to exist as international legal person.
In other words, on the eve of the independence of Azerbaijan, the unlawfulness within the Soviet legal system of any unification of NKAO with Armenia without Azerbaijan’s consent was confirmed at the highest constitutional level. Azerbaijan did not so consent, so that the definition of the territory of Azerbaijan as it proceeded to independence and in the light of the applicable law clearly included the territory of Karabakh region.
After the collapse of the USSR in December 1991, the international legitimacy of the boundaries of newly independent States was secured by the international legal doctrine of uti possidetis juris. With it, the former administrative borders of Azerbaijan SSR, which included NKAO, were recognized by international law as the legitimate borders of the newly independent Republic of Azerbaijan. It was later reaffirmed in the UN Security Council resolutions 822 (1993), 853 (1993), 874 (1993) and 884 (1993).
Without any valid legal grounds for the annexation of the Karabakh region, Armenia resorted to using the principle of the right to self-determination. However, the principle of self-determination cannot be interpreted to include a right of secession. Armenia’s actions on “secession” from an independent Azerbaijan on the grounds of self-determination violates the universally accepted norms of the sovereignty and territorial integrity of states as well as other relevant international legal principles, such as rule prohibiting the use of force against territorial integrity of states.
 By the Decision of the Supreme Soviet of the Republic of Azerbaijan NKAO as an administrative territorial unit ceased to exist on November 26, 1991